Throw away cutter

Abstract

A disposable cutter has a cutter body formed with chip pockets and a plurality of disposable inserts having cutting edges. Each pocket is formed at least at the front or inner side of the body with a spherical blind groove portion. The center of radius of curvature of the spherical blind groove portion is located on an imaginary line drawn from the front end of each cutting edge toward the pocket at a substantially right angle with respect to each cutting edge.

What is claimed is: 
     
       1. A cutter comprising: a substantially cylindrical cutter body adapted to be rotated about its central axis in a rotational direction;   a plurality of disposable cutting inserts mounted to an upper end face of said substantially cylindrical cutter body, said cutting inserts having rake faces and having cutting edges which extend obliquely relative to radial lines radiating from said central axis of said cutter body and intersecting said cutting edges, respectively; and   wherein chip pockets are formed in said upper end face of said cutter body adjacent said rake faces of said cutting inserts, respectively, each of said chip pockets opening substantially radially outwardly through an outer circumferential sidewall of said substantially cylindrical cutter body and having a radially inner portion bounded by a back wall which is substantially spherically concave shaped and faces substantially radially outwardly and rearwardly with respect to the rotational direction of said cutter body.   
     
     
       2. A cutter as recited in claim 1, wherein each of said chip pockets is substantially in the form of a groove which extends in a direction substantially parallel with said cutting edge of said cutting insert and which is closed at its radially inner end by said back wall and opens at its radially outer end through said outer circumferential sidewall of said substantially cylindrical cutter body.   
     
     
       3. A cutter as recited in claim 1, wherein for each of said chip pockets, a center of curvature of said spherically concave back wall is located on a line extending perpendicular from said cutting edge of said cutting insert.   
     
     
       4. A cutter as recited in claim 1, wherein said rake faces of said cutting inserts have positive axial rake angles, respectively.